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Possible role of glial cells in the onset and progression of Lyme neuroborreliosis.

Ramesh G, Borda JT, Gill A, Ribka EP, Morici LA, Mottram P, Martin DS, Jacobs MB, Didier PJ, Philipp MT - J Neuroinflammation (2009)

Bottom Line: CCL2 and CXCL13 were found in microglia as well as in endothelial cells, macrophages and T cells.Importantly, the DRG of infected animals showed significant satellite cell and neuronal apoptosis.Our results support the notion that innate responses of glia to B. burgdorferi initiate/mediate the inflammation seen in acute LNB, and show that neuronal apoptosis occurs in this context.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, LA, USA. gramesh@tulane.edu

ABSTRACT

Background: Lyme neuroborreliosis (LNB) may present as meningitis, cranial neuropathy, acute radiculoneuropathy or, rarely, as encephalomyelitis. We hypothesized that glia, upon exposure to Borrelia burgdorferi, the Lyme disease agent, produce inflammatory mediators that promote the acute cellular infiltration of early LNB. This inflammatory context could potentiate glial and neuronal apoptosis.

Methods: We inoculated live B. burgdorferi into the cisterna magna of rhesus macaques and examined the inflammatory changes induced in the central nervous system (CNS), and dorsal root nerves and ganglia (DRG).

Results: ELISA of the cerebrospinal fluid (CSF) showed elevated IL-6, IL-8, CCL2, and CXCL13 as early as one week post-inoculation, accompanied by primarily lymphocytic and monocytic pleocytosis. In contrast, onset of the acquired immune response, evidenced by anti-B. burgdorferi C6 serum antibodies, was first detectable after 3 weeks post-inoculation. CSF cell pellets and CNS tissues were culture-positive for B. burgdorferi. Histopathology revealed signs of acute LNB: severe multifocal leptomeningitis, radiculitis, and DRG inflammatory lesions. Immunofluorescence staining and confocal microscopy detected B. burgdorferi antigen in the CNS and DRG. IL-6 was observed in astrocytes and neurons in the spinal cord, and in neurons in the DRG of infected animals. CCL2 and CXCL13 were found in microglia as well as in endothelial cells, macrophages and T cells. Importantly, the DRG of infected animals showed significant satellite cell and neuronal apoptosis.

Conclusion: Our results support the notion that innate responses of glia to B. burgdorferi initiate/mediate the inflammation seen in acute LNB, and show that neuronal apoptosis occurs in this context.

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Related in: MedlinePlus

Histopathological evaluation and immunofluorescence staining of lesions in the brain, dorsal root nerves and DRG. A) Composite light microscope image of leptomeningitis in the brain of a B. burgdorferi-inoculated animal (DR50) showing lymphocytic, plasmacytic and monocytic infiltration by hematoxylin and eosin staining, as well as immunohistochemical staining showing CD3-labeled T cells, CD-20-labeled B cells, and CD68-labeled macrophages. B) Confocal micrograph showing immunofluorescence staining of CD3-labeled T cells (green), CD20-labeled B cells (blue) as well as CD68-labeling macrophages (red) in a representative inflammatory lesion from the meninges of animal DR50. C) FITC-labeled B. burgdorferi antigen (green) in the vicinity of CD3-staining T cells (red) and CD68-staining macrophages in lesions found in the frontal cortex of animal DR50. D) Radiculitis in the dorsal root of a cervical spinal nerve proximal to the ganglion of animal DH50. There is abundant lymphocytic, and monocytic infiltration as well as plasma cells. A few adjacent nerve fibers have swollen sheaths. E) Chronic-type inflammation of DRG from animal DH50 showing infiltrates of lymphocytes, plasma cells, and monocytes. F) B. burgdorferi antigen stained with antibody to B. burgdorferi labeled with FITC, in the vicinity of the CD3-staining T cells (red) in lesions found in DRG of animal DR50.
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Figure 4: Histopathological evaluation and immunofluorescence staining of lesions in the brain, dorsal root nerves and DRG. A) Composite light microscope image of leptomeningitis in the brain of a B. burgdorferi-inoculated animal (DR50) showing lymphocytic, plasmacytic and monocytic infiltration by hematoxylin and eosin staining, as well as immunohistochemical staining showing CD3-labeled T cells, CD-20-labeled B cells, and CD68-labeled macrophages. B) Confocal micrograph showing immunofluorescence staining of CD3-labeled T cells (green), CD20-labeled B cells (blue) as well as CD68-labeling macrophages (red) in a representative inflammatory lesion from the meninges of animal DR50. C) FITC-labeled B. burgdorferi antigen (green) in the vicinity of CD3-staining T cells (red) and CD68-staining macrophages in lesions found in the frontal cortex of animal DR50. D) Radiculitis in the dorsal root of a cervical spinal nerve proximal to the ganglion of animal DH50. There is abundant lymphocytic, and monocytic infiltration as well as plasma cells. A few adjacent nerve fibers have swollen sheaths. E) Chronic-type inflammation of DRG from animal DH50 showing infiltrates of lymphocytes, plasma cells, and monocytes. F) B. burgdorferi antigen stained with antibody to B. burgdorferi labeled with FITC, in the vicinity of the CD3-staining T cells (red) in lesions found in DRG of animal DR50.

Mentions: Histopathological evaluation of tissues collected from the 2 animals that were euthanized at 6 weeks PI revealed severe multifocal lymphocytic, monocytic and plasmacytic leptomeningitis in the brain and spinal cord. Radiculitis was evidenced by inflammatory infiltrates in the nerve roots of the cervical, thoracic, lumbar and sacral spinal cord. Similar lesions were seen in animal DH50, which was euthanized at 12 weeks PI. A representative image of brain leptomeningitis is shown in Fig 4A. The cellular infiltrates contained, in decreasing order of abundance, B lymphocytes (CD20+), T lymphocytes (CD3+), and monocyte/macrophages (CD68+). Figure 4B depicts a confocal micrograph of a lesion found in the dura mater of animal DR50 showing the presence of T cells, B cells and monocyte/macrophages. Inflammatory infiltrates in the vicinity of B. burgdorferi antigen were observed in the dura mater (not shown) and frontal cortex of animals DR50 (Fig. 4C), EL81 and DH50. As with the meninges, the parenchymal cell infiltrates were composed chiefly by B and T lymphocytes and few macrophages. B. burgdorferi antigen was also present in tissues collected from the periventricular areas and spinal cord of infected animals (not shown). Radiculitis seen as inflammation of the dorsal roots collected from the cervical, thoracic, lumbar, and sacral spinal cord was observed in animals DR50, EL81 (6-week-long infection) and DH50 (12-week). A representative image of radiculitis is depicted in Fig. 4D. Inflammation and presence of B. burgdorferi antigen was also observed in the DRG, in animals DR50 and DH50. A chronic type of inflammation of DRG from animal DH50 is shown in Fig 4E. The presence of B. burgdorferi antigen in the vicinity of CD3-labeling-T cells in the DRG is shown in Fig. 4F. No inflammatory lesions were detected at necropsy in the remaining animals that were given a B. burgdorferi inoculation and were euthanized at 12-weeks PI (EP51 and CH82), or in the control animals.


Possible role of glial cells in the onset and progression of Lyme neuroborreliosis.

Ramesh G, Borda JT, Gill A, Ribka EP, Morici LA, Mottram P, Martin DS, Jacobs MB, Didier PJ, Philipp MT - J Neuroinflammation (2009)

Histopathological evaluation and immunofluorescence staining of lesions in the brain, dorsal root nerves and DRG. A) Composite light microscope image of leptomeningitis in the brain of a B. burgdorferi-inoculated animal (DR50) showing lymphocytic, plasmacytic and monocytic infiltration by hematoxylin and eosin staining, as well as immunohistochemical staining showing CD3-labeled T cells, CD-20-labeled B cells, and CD68-labeled macrophages. B) Confocal micrograph showing immunofluorescence staining of CD3-labeled T cells (green), CD20-labeled B cells (blue) as well as CD68-labeling macrophages (red) in a representative inflammatory lesion from the meninges of animal DR50. C) FITC-labeled B. burgdorferi antigen (green) in the vicinity of CD3-staining T cells (red) and CD68-staining macrophages in lesions found in the frontal cortex of animal DR50. D) Radiculitis in the dorsal root of a cervical spinal nerve proximal to the ganglion of animal DH50. There is abundant lymphocytic, and monocytic infiltration as well as plasma cells. A few adjacent nerve fibers have swollen sheaths. E) Chronic-type inflammation of DRG from animal DH50 showing infiltrates of lymphocytes, plasma cells, and monocytes. F) B. burgdorferi antigen stained with antibody to B. burgdorferi labeled with FITC, in the vicinity of the CD3-staining T cells (red) in lesions found in DRG of animal DR50.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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Figure 4: Histopathological evaluation and immunofluorescence staining of lesions in the brain, dorsal root nerves and DRG. A) Composite light microscope image of leptomeningitis in the brain of a B. burgdorferi-inoculated animal (DR50) showing lymphocytic, plasmacytic and monocytic infiltration by hematoxylin and eosin staining, as well as immunohistochemical staining showing CD3-labeled T cells, CD-20-labeled B cells, and CD68-labeled macrophages. B) Confocal micrograph showing immunofluorescence staining of CD3-labeled T cells (green), CD20-labeled B cells (blue) as well as CD68-labeling macrophages (red) in a representative inflammatory lesion from the meninges of animal DR50. C) FITC-labeled B. burgdorferi antigen (green) in the vicinity of CD3-staining T cells (red) and CD68-staining macrophages in lesions found in the frontal cortex of animal DR50. D) Radiculitis in the dorsal root of a cervical spinal nerve proximal to the ganglion of animal DH50. There is abundant lymphocytic, and monocytic infiltration as well as plasma cells. A few adjacent nerve fibers have swollen sheaths. E) Chronic-type inflammation of DRG from animal DH50 showing infiltrates of lymphocytes, plasma cells, and monocytes. F) B. burgdorferi antigen stained with antibody to B. burgdorferi labeled with FITC, in the vicinity of the CD3-staining T cells (red) in lesions found in DRG of animal DR50.
Mentions: Histopathological evaluation of tissues collected from the 2 animals that were euthanized at 6 weeks PI revealed severe multifocal lymphocytic, monocytic and plasmacytic leptomeningitis in the brain and spinal cord. Radiculitis was evidenced by inflammatory infiltrates in the nerve roots of the cervical, thoracic, lumbar and sacral spinal cord. Similar lesions were seen in animal DH50, which was euthanized at 12 weeks PI. A representative image of brain leptomeningitis is shown in Fig 4A. The cellular infiltrates contained, in decreasing order of abundance, B lymphocytes (CD20+), T lymphocytes (CD3+), and monocyte/macrophages (CD68+). Figure 4B depicts a confocal micrograph of a lesion found in the dura mater of animal DR50 showing the presence of T cells, B cells and monocyte/macrophages. Inflammatory infiltrates in the vicinity of B. burgdorferi antigen were observed in the dura mater (not shown) and frontal cortex of animals DR50 (Fig. 4C), EL81 and DH50. As with the meninges, the parenchymal cell infiltrates were composed chiefly by B and T lymphocytes and few macrophages. B. burgdorferi antigen was also present in tissues collected from the periventricular areas and spinal cord of infected animals (not shown). Radiculitis seen as inflammation of the dorsal roots collected from the cervical, thoracic, lumbar, and sacral spinal cord was observed in animals DR50, EL81 (6-week-long infection) and DH50 (12-week). A representative image of radiculitis is depicted in Fig. 4D. Inflammation and presence of B. burgdorferi antigen was also observed in the DRG, in animals DR50 and DH50. A chronic type of inflammation of DRG from animal DH50 is shown in Fig 4E. The presence of B. burgdorferi antigen in the vicinity of CD3-labeling-T cells in the DRG is shown in Fig. 4F. No inflammatory lesions were detected at necropsy in the remaining animals that were given a B. burgdorferi inoculation and were euthanized at 12-weeks PI (EP51 and CH82), or in the control animals.

Bottom Line: CCL2 and CXCL13 were found in microglia as well as in endothelial cells, macrophages and T cells.Importantly, the DRG of infected animals showed significant satellite cell and neuronal apoptosis.Our results support the notion that innate responses of glia to B. burgdorferi initiate/mediate the inflammation seen in acute LNB, and show that neuronal apoptosis occurs in this context.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, LA, USA. gramesh@tulane.edu

ABSTRACT

Background: Lyme neuroborreliosis (LNB) may present as meningitis, cranial neuropathy, acute radiculoneuropathy or, rarely, as encephalomyelitis. We hypothesized that glia, upon exposure to Borrelia burgdorferi, the Lyme disease agent, produce inflammatory mediators that promote the acute cellular infiltration of early LNB. This inflammatory context could potentiate glial and neuronal apoptosis.

Methods: We inoculated live B. burgdorferi into the cisterna magna of rhesus macaques and examined the inflammatory changes induced in the central nervous system (CNS), and dorsal root nerves and ganglia (DRG).

Results: ELISA of the cerebrospinal fluid (CSF) showed elevated IL-6, IL-8, CCL2, and CXCL13 as early as one week post-inoculation, accompanied by primarily lymphocytic and monocytic pleocytosis. In contrast, onset of the acquired immune response, evidenced by anti-B. burgdorferi C6 serum antibodies, was first detectable after 3 weeks post-inoculation. CSF cell pellets and CNS tissues were culture-positive for B. burgdorferi. Histopathology revealed signs of acute LNB: severe multifocal leptomeningitis, radiculitis, and DRG inflammatory lesions. Immunofluorescence staining and confocal microscopy detected B. burgdorferi antigen in the CNS and DRG. IL-6 was observed in astrocytes and neurons in the spinal cord, and in neurons in the DRG of infected animals. CCL2 and CXCL13 were found in microglia as well as in endothelial cells, macrophages and T cells. Importantly, the DRG of infected animals showed significant satellite cell and neuronal apoptosis.

Conclusion: Our results support the notion that innate responses of glia to B. burgdorferi initiate/mediate the inflammation seen in acute LNB, and show that neuronal apoptosis occurs in this context.

Show MeSH
Related in: MedlinePlus